Adulthood has been a neglected area of research into autism spectrum disorder (autism) but is currently experiencing an increase in interest. Recent UK data estimate the prevalence of autism in adults at 1.1 per cent (Brugha et al., 2016). In early data from the Autism CRC Australian Longitudinal Study of School Leavers with Autism aged 15 to 25 years, half of participants self-reported diagnosis at nine years of age or older. The Autism CRC Australian Longitudinal Study of Adults with Autism (ALSAA; age 25+ years) found that 94 per cent of self-reporting individuals received an autism diagnosis at 10 years or older. Thus, many adolescents and adults with autism may not be identified until they come to the psychologist’s attention when they present with other psychological problems.
International research shows that outcomes for adults with autism are mixed, with lower rates of social inclusion and employment and often poor daily-living skills, and poor mental and physical health. The best outcomes appear to be for those with higher IQ and better language skills, but around half of adults with autism remain living at home, less than half engage in some form of employment or education, few marry and only about 25 per cent have friends (Howlin & Moss, 2012).
Transitions
Periods of transition can be particularly stressful for adults with autism, and one of these is the transition out of secondary education. Research with Victorian students with autism currently in tertiary education (Cai & Richdale, 2016) indicated formal transition plans were often missing, many students felt the need of extra support, and comorbid anxiety, depression and executive function difficulties were a major contributor to student difficulties. Families remained a significant source of support and over half of students lived at home. Disclosure of an autism diagnosis was identified as an important issue when transitioning and in settling into post-secondary education. Similarly, early analysis showed 72 per cent of young people (15-25 years) in the Autism CRC school leavers’ study found school or university challenging. Only 41 per cent had received transition supports, but 73 per cent would have liked supports.
Employment
Australian Bureau of Statistics (2014) data show that adults with autism have the lowest level of employment of any disability, with only 42 per cent being employed, compared with 53 per cent across other disabilities. Consistent with this only 54 per cent of adults in the Autism CRC ALSAA had some form of employment. Australian findings are consistent with international research, with 56 per cent of young Swedish adults with autism not working or studying even though all but one had completed school and 40 per cent were university educated (Hirvikoski & Blomqvist, 2015). Where individuals with autism are employed they are frequently underemployed in relation to skills and qualifications and are in part-time work (Hedley et al., in press). Current employment research is very broad and lacks controls, with poorly characterised participants, small samples and poor outcome measures. Supported programs generally lead to better outcomes, both from the perspectives of employment hours and wages, and social outcomes, while comorbidity is associated with less favourable employment outcomes for adults with autism (Hedley et al., 2016).
The Olga Tennison Autism Research Centre has been evaluating outcomes for adults with autism participating in the Dandelion Program, where trainees work as software test analysts in a supported environment within the Federal Department of Human Services (DHS). The program is a joint initiative of DHS and Hewlett Packard Enterprise (HPE). In a focus group study (Hedley et al., in press) trainees, support staff, co-workers and family members reported on their experiences in the first seven months of the program. Factors supporting work success included organisational and leadership support, modifications to the work environment when needed, co-worker advice and a workplace consultant. Challenges included factors associated with autistic characteristics, work stress, task-related difficulties and factors related to the individual. Overall there were a range of work-related and personal outcomes that were rated as positive.
Mental health
Individuals with autism are at high risk for one or more comorbid mental health conditions, most commonly anxiety and depression (Croen et al., 2015; Russell et al., 2016; van Steensel, Bogels, & Perrin, 2011), which exceed prevalence rates reported in non-autistic individuals (Croen et al., 2015). Initial Australian data from the Autism CRC longitudinal studies, showed that 46 per cent of adults aged 25 to 80 years reported a current diagnosis of depression and 54 per cent reported an anxiety diagnosis, while for the 15 to 25 year-olds, 52 per cent reported anxiety, 27 per cent had depression and 27 per cent reported ADHD.
Individuals referred as adults for autism diagnosis are likely to have high rates of mental health problems. Russell et al. (2016) retrospectively reviewed assessments for 859 adults referred for a multidisciplinary autism diagnostic assessment. Just over half of the individuals received an autism diagnosis at average age 30.6 years and comorbid psychiatric conditions were common in both adults diagnosed with autism and those not receiving a diagnosis. Those with an autism diagnosis were differentiated by a significantly higher occurrence of any anxiety disorder or obsessive compulsive disorder. Croen et al. (2015) examined 1,507 adults with autism who were members of a Northern Californian Medical Care Program and found they had elevated scores on anxiety, depression and a range of other mental health disorders when compared with 15,070 randomly matched non-autistic members. However, drug and alcohol abuse was not different between the two groups.
Thus, contemporary evidence supports the view that those with autism are at high risk for one or more comorbid psychiatric diagnoses, with anxiety and mood disorders being most common.
Physical health
Little attention has been paid to physical health or medical complaints in adults with autism, but emerging evidence indicates a high rate of problems (Croen et al., 2015; Jones et al., 2016). Adults with autism are at risk for a range of potentially serious medical complaints, which are significantly more common than in a non-autistic comparison group. These disorders included allergy, cardiovascular disease, obesity, neurologic disorders, gastrointestinal disorders and conditions associated with nutrition, which were present in approximately 30 to 40 per cent of adults with autism (Croen et al., 2015).
Sleep is one medical health condition with a body of autism research. Adults with autism have more frequent sleep difficulties than those without autism (Limoges, Mottron, Bolduc, Berthiaume, & Godbout, 2005; Tani et al., 2003), and poor sleep may be related to anxiety (Tani et al., 2003). Autism CRC longitudinal studies indicated two thirds of ALSAA adults and around half of school leavers have poor sleep, which is related to anxiety symptoms. Adults with autism frequently meet criteria for insomnia (28%) and/or a circadian sleep-wake disorder (44%) (Baker & Richdale, 2015, 2017); like children with autism, adults typically have one or more of increased sleep onset latency and night waking, and reduced total night sleep and sleep efficiency. Sleep apnoea is more common in adults with autism compared with non-autistic adults (Croen et al., 2015), possibly associated with the high rate of obesity.
Quality of life
Poor employment prospects, low community engagement and high rates of mental and physical health problems affect quality of life (QoL). Across the lifespan, individuals with autism have significantly lower QoL than do individuals without autism. There is a need for QoL research, especially in older adults (van Heijst & Geurts, 2015). Consistent with this, the Autism CRC ALSAA data show that adults self-report significantly poorer QoL across all QoL domains than do similar age Australian adults. Adults with ASD experience high stress and poor coping (Hirvikoski & Blomqvist, 2015), and our early data indicate a high incidence of bullying (66%) for the young people in the Autism CRC school leavers’ study. Perceived stress and bullying are two factors that predict QoL in able adults with autism (Hong, Bishop-Fitzpatrick, Smith, Greenberg, & Malick, 2016).
Poor executive function may also contribute to difficulties experienced by cognitively able adults with autism who often show poor flexibility, organisation and planning. Poorer executive functioning in Netherlands higher education students with autism was associated with poor QoL (Dijkhuis, Ziermans, Van Rijn, Staal, & Swaab, 2016), while in Australian students with autism, self-reported difficulties with planning, organisation and coping with change affected higher education success (Cai & Richdale, 2016). Flexibility and planning are also related to anxiety, depression and adaptive functioning in adults on the spectrum with above average full scale IQ (Wallace et al., 2016).
Implications for psychology practice
The state of intervention research for adults with autism is poor. There is some evidence that modifications of cognitive behaviour therapy and mindfulness-based therapies can assist with mental health issues (Kerns, Roux, Cunneil, & Shattuck, 2016; Kiep, Spek, & Hoeben, 2015; Vasa et al., 2014), however, valid and reliable measures of assessment and treatment for individuals with autism are lacking (Brugha et al., 2015; Lecavalier et al., 2014). Overall, adult research is in its infancy and most current knowledge pertains to younger adults. Differential diagnosis of autism and mental health problems, mental health and sleep interventions, transition support, bullying, employment support, and supports for those with significant physical health conditions are all areas of need and provide scope for engagement across the range of psychological areas of research and practice.
Acknowledgements
Autism CRC data are from the Autism CRC Longitudinal Studies with permission from project leaders and the Autism CRC. The authors acknowledge the financial support of the Autism CRC that has made possible the collection of this longitudinal data. The Autism CRC is established and supported under the Australian Government's Cooperative Research Centres Program.
In referring to this Autism CRC data we thank the longitudinal study participants and their families and the longitudinal study teams at the University of New South Wales (Prof Julian Trollor, Dr Kitty-Rose Foley, Ms Jane Hwang), and La Trobe University (Assoc Prof Amanda Richdale, Dr Mirko Uljarevi?, Ms Ru Cai).